George Varghese

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George Varghese (born 1960) is a Principal Researcher at Microsoft Research. Before joining MSR's lab in Silicon Valley in 2013, he was a Professor of Computer Science at the University of California San Diego, where he led the Internet Algorithms Lab and also worked with the Center for Network Systems and the Center for Internet Epidemiology. [1] He is the author of the textbook Network Algorithmics, published by Morgan Kaufmann [2] in 2004.

Contents

Education

Varghese received his B.Tech in electrical engineering from IIT Bombay in 1981, his M.S. in computer studies from NCSU in 1983 and his Ph.D. in computer science from MIT in 1993, where his advisor was Nancy Lynch. [3] He has been a Fellow of the ACM since 2002. [4]

Research

Transparent Bridge Architecture

Before his Ph.D., George spent several years as part of the network architecture and advanced development group at Digital Equipment Corporation, where he wrote the first specification for the first transparent bridge architecture (based on the inventions of Mark Kempf and Radia Perlman).[ citation needed ] After several iterations and other authors, this became the IEEE 802 bridge specification, a widely implemented standard that is the basis of the billion dollar transparent bridging industry{{ According to whom }}.[ citation needed ] He was also part of the DEC team that invented the Gigaswitch and the Giganet (a precursor to Gigabit Ethernet).[ citation needed ]

Network Algorithmics

Varghese is best known for helping define network algorithmics, a field of study which resolves networking bottlenecks using interdisciplinary techniques that include changes to hardware and operating systems as well as efficient algorithms.[ citation needed ]

His contributions to network algorithmics include Deficit Round Robin (co-invented with M. Shreedhar), a scheduling algorithm that is widely used in routers, and timing wheels (with Tony Lauck), an algorithm for fast timers that is used as the basis of fast timers in Linux and FreeBSD.[ citation needed ]

IP lookup and packet classification

Varghese has also worked extensively on fast IP lookup and packet classification. His work with G. Chandranmenon on Threaded indexes predates the work done at Cisco Systems and Juniper Networks on tag switching [ citation needed ]. His work on multibit tries (with V. Srinivasan) has been used by a number of companies including Microsoft. His work on scalable IP packet lookup (with Waldvogel and Turner) for longer addresses such as IPv6 is being considered for use by Linux.[ citation needed ]

George also worked with Eatherton and Dittia on the Tree bitmap IP lookup algorithm that is used in Cisco's CRS-1 router, which many[ who? ] believe to be the fastest router in the world[ citation needed ]. Tree bitmap and hypercuts (with Sumeet Singh and Florin Baboescu) appear to be among the best algorithms (excluding CAMs) for IP lookup and packet classification today.[ citation needed ]

Self stabilization

George is also known for his contributions to the theoretical field of self-stabilization (a form of fault-tolerance), where he has helped (with various colleagues) pioneer several general techniques such as local checking, local correction, and counter flushing.[ citation needed ]

NetSift

Varghese co-founded NetSift Inc. (with Sumeet Singh) in 2004, serving as president and CTO. NetSift helped pioneer the notion of automated signature extraction for security and helped to introduce the use of streaming algorithms for network measurement and security at speeds greater than 10 Gbit/s. His work with Cristian Estan on multistage filters has been widely used in industry. NetSift was acquired in June 2005 by Cisco Systems as part of the Modular Switching Group.[ citation needed ]

Awards and honors

Selected publications

Related Research Articles

Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints, the labels identify established paths between endpoints. MPLS can encapsulate packets of various network protocols, hence the multiprotocol component of the name. MPLS supports a range of access technologies, including T1/E1, ATM, Frame Relay, and DSL.

<span class="mw-page-title-main">Router (computing)</span> Device that forwards data packets between computer networks

A router is a computer and networking device that forwards data packets between computer networks, including internetworks such as the global Internet.

The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Major internet applications such as the World Wide Web, email, remote administration, and file transfer rely on TCP, which is part of the Transport layer of the TCP/IP suite. SSL/TLS often runs on top of TCP.

A network operating system (NOS) is a specialized operating system for a network device such as a router, switch or firewall.

The Routing Information Protocol (RIP) is one of the oldest distance-vector routing protocols which employs the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from source to destination. The largest number of hops allowed for RIP is 15, which limits the size of networks that RIP can support.

Deficit Round Robin (DRR), also Deficit Weighted Round Robin (DWRR), is a scheduling algorithm for the network scheduler. DRR is, like weighted fair queuing (WFQ), a packet-based implementation of the ideal Generalized Processor Sharing (GPS) policy. It was proposed by M. Shreedhar and G. Varghese in 1995 as an efficient and fair algorithm.

NetBIOS over TCP/IP is a networking protocol that allows legacy computer applications relying on the NetBIOS API to be used on modern TCP/IP networks.

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Nagle's algorithm is a means of improving the efficiency of TCP/IP networks by reducing the number of packets that need to be sent over the network. It was defined by John Nagle while working for Ford Aerospace. It was published in 1984 as a Request for Comments (RFC) with title Congestion Control in IP/TCP Internetworks in RFC 896.

Cisco Express Forwarding (CEF) is an advanced layer 3 switching technology used mainly in large core networks or the Internet to enhance the overall network performance. Although CEF is a Cisco proprietary protocol other vendors of multi-layer switches or high-capacity routers offer a similar functionality where layer-3 switching or routing is done in hardware instead of by software and the (central) CPU.

The Skype protocol is a proprietary Internet telephony network used by Skype. The protocol's specifications have not been made publicly available by Skype and official applications using the protocol are closed-source.

<span class="mw-page-title-main">Data plane</span> Router architecture

In routing, the data plane, sometimes called the forwarding plane or user plane, defines the part of the router architecture that decides what to do with packets arriving on an inbound interface. Most commonly, it refers to a table in which the router looks up the destination address of the incoming packet and retrieves the information necessary to determine the path from the receiving element, through the internal forwarding fabric of the router, and to the proper outgoing interface(s).

Extremely Opportunistic Routing (ExOR) is a combination of routing protocol and media access control for a wireless ad hoc network, invented by Sanjit Biswas and Robert Morris of the MIT Artificial Intelligence Laboratory, and described in a 2005 paper. A very similar opportunistic routing scheme was also independently proposed by Zhenzhen Ye and Yingbo Hua from University of California, Riverside and presented in a paper in 2005. Previously open source, ExOR was available in 2005 but is no longer obtainable. The broadcast and retransmission strategies used by the algorithm were already described in the literature. ExOR is valuable because it can operate available digital radios to use some previously impractical algorithmic optimizations.

Stefan Savage is an American computer science researcher, currently a Professor in the Systems and Networking Group at the University of California, San Diego. There, he holds the Irwin and Joan Jacobs Chair in Information and Computer Science. Savage is widely cited in computer security, particularly in the areas of email spam, network worms and malware propagation, distributed denial of service (DDOS) mitigation and traceback, automotive hacking and wireless security. He received his undergraduate degree at Carnegie Mellon and his Ph.D. from the University of Washington (2002).

Karn's algorithm addresses the problem of getting accurate estimates of the round-trip time for messages when using the Transmission Control Protocol (TCP) in computer networking. The algorithm, also sometimes termed as the Karn-Partridge algorithm was proposed in a paper by Phil Karn and Craig Partridge in 1987.

The uIP is an open-source implementation of the TCP/IP network protocol stack intended for use with tiny 8- and 16-bit microcontrollers. It was initially developed by Adam Dunkels of the Networked Embedded Systems group at the Swedish Institute of Computer Science, licensed under a BSD style license, and further developed by a wide group of developers.

Bufferbloat is a cause of high latency and jitter in packet-switched networks caused by excess buffering of packets. Bufferbloat can also cause packet delay variation, as well as reduce the overall network throughput. When a router or switch is configured to use excessively large buffers, even very high-speed networks can become practically unusable for many interactive applications like voice over IP (VoIP), audio streaming, online gaming, and even ordinary web browsing.

In digital communications networks, packet processing refers to the wide variety of algorithms that are applied to a packet of data or information as it moves through the various network elements of a communications network. With the increased performance of network interfaces, there is a corresponding need for faster packet processing.

Traffic classification is an automated process which categorises computer network traffic according to various parameters into a number of traffic classes. Each resulting traffic class can be treated differently in order to differentiate the service implied for the data generator or consumer.

References

  1. Dame, Marketing Communications: Web | University of Notre. "George Varghese". NSF Workshop. Retrieved 2022-10-17.
  2. "Network Algorithmics:An Interdisciplinary Approach to Designing Fast Networked Devices". Elsevier: Morgan Kaufmann. Archived from the original on 2011-07-10. Retrieved December 22, 2006.
  3. George Varghese at the Mathematics Genealogy Project
  4. "George Varghese – Award Winner". Association for Computing Machinery . Retrieved 31 October 2013.
  5. National Academy of Engineering Elects 84 Members and 22 Foreign Members, February 8, 2017, retrieved 2017-05-02.